Tires commonly utilize sipes in the tire tread for snow and wet traction. Metal blades are typically used to mold the sipes in the tire tread. As shown in FIG. 7a, these blades A are typically designed with a radiused edge B at the blade bottom in order to minimize the block tearing. However the tread block tends to tear at the vertical slit C formed in the sides of the tread block. As shown in FIG. 7B, block tearing is also problematic for blocks joined by tie bars, because the blade sharp edges tends to cut deep into the tread area located next to the tie bar, resulting in an sharp corner and high stress concentration. Also, when the blade is removed from the tire block tearing may occur, particularly at the edges of the tread block. Thus an improved blade and sipe geometrical configuration is desired, which alleviates all the disadvantages described above as well as a blade design that increases the blades resistance to bending.